What do I do if this boy I like says he likes me too, but he's got a girlfriend already? :(

I really liked a guy who was in a relationship and he started to speak to me more and more but I decided to stop talking to him because I didnt want to get my hopes up.
A few months later he dumped his girlfriend and we started to talk again, he asked why I stopped talking to him before and laughed because he said he felt the same way about me and wasnt happy in his relationship. He said that he was just about to dump his gf and wanted to get to know me better but. Then we stopped speaking. But after he thought I wasnt interested in him he tried to give it another go with his gf, but it didn't work out. We started seeing each other and have now been going out for a few months. So honestly, just go for it, see how he feels!

Tell him to choose. If he chooses you great if not then move on

Don't go down this route. You've got to work out who's the most important person in your life. There are plenty of lads you could date. What if you fell out with your friend over it and then you got with this lad and he cheated on you and got with someone else it's your choice but THINK CAREFULLY first, good luck.

Tell him to break up with the girl or fight the girl for him if he's worth it.